This invention relates to a comb-shaped element for receiving products supplied by a conveying mat of a conveyor, which comb-shaped element comprises a body with an essentially closed top surface and a plurality of teeth formed on the body and extending parallel to each other.
Such a comb-shaped element is disclosed, for instance, in U.S. Pat. No. 2,237,345 or in U.S. Pat. No. 4,051,949, which patent specifications describe an endless conveying mat preferably made up of synthetic plastics modules, wherein at the "end" of the mat, i.e., where it has been passed around driving wheels arranged transversely to the direction of advancement, the toothed projections of the comb engage between the successive upright ribs of the modules to thereby obtain, for the benefit of the products conveyed over the mat, a flowing transition from the moving transport part, the mat, to a stationary transport part, the body or bearing surface of the comb.
The known comb-shaped elements are fixedly connected to a frame of the conveyor by means of, for instance, bolts and nuts. This entails a number of drawbacks. Firstly, for the known fastening means, openings are present in the top surface of the bearing surface of the comb-shaped element to receive these fastening means and to be able to secure them. These openings are easily soiled and cannot be properly cleaned, which is undesirable, particularly in the foodstuffs industry. Secondly, it happens regularly that a tooth of the comb-shaped element is bent, for instance because, in the case of glass transport, a fragment of glass gets stuck under a tooth and presses it upwards. Such a damaged comb-shaped element must be replaced, which, in the case of the known fastening means, is a rather time-consuming operation, in particular when the access openings for the fastening means as described above are soiled. The entire conveyor must be stopped during the replacement operation, which is economically unattractive. Thirdly, when the known fastening means are used, problems can arise in the case where the conveyor and the combs are exposed to large temperature fluctuations, such as for instance when such a conveyor is used in a pasteurizer, in particular when it is periodically disinfected. The fact is that if the chain mat expands or shrinks as a result of temperature changes, the driving wheels, which are mounted on a common shaft, can follow this movement of the mat when, as is disclosed in U.S. Pat. No. 3,724,285, only the central driving wheel is fixedly mounted on the shaft and the other wheels can shift over the shaft in lateral direction relative to this central wheel. The combs mounted fixedly on the frame, however, can follow the lateral displacement of the modules only to a limited extent, even when the holes for the attachment of the comb to the frame by means of bolts and nuts are slotted. This results in a forcing of the teeth in lateral direction, which is not beneficial to the useful life of the mat modules and the combs.